any of the more or less continuous military expeditions in the 11th to 13th centuries when Christian powers of Europe tried to recapture the Holy Land from the Muslims
go on a crusade; fight a holy war
exert oneself continuously, vigorously, or obtrusively to gain an end or engage in a crusade for a certain cause or person; be an advocate for; "The liberal party pushed for reforms"; "She is crusading for women's rights"; "The Dean is pushing for his favorite candidate"
notify, usually in advance; "I warned you that I would ask some difficult questions"
ask to go away; "The old man warned the children off his property"
notify of danger, potential harm, or risk; "The director warned him that he might be fired"; "The doctor warned me about the dangers of smoking"
admonish or counsel in terms of someone's behavior; "I warned him not to go too far"; "I warn you against false assumptions"; "She warned him to be quiet"
a successful ending of a struggle or contest; "a narrow victory"; "the general always gets credit for his army's victory"; "clinched a victory"; "convincing victory"; "the agreement was a triumph for common sense"
requiring effort or concentration; complex and not easy to answer or solve; "raised serious objections to the proposal"; "the plan has a serious flaw"
of great consequence; "marriage is a serious matter"
concerned with work or important matters rather than play or trivialities; "a serious student of history"; "a serious attempt to learn to ski"; "gave me a serious look"; "a serious young man"; "are you serious or joking?"; "Don't be so serious!"
come into sight or view; "He suddenly appeared at the wedding"; "A new star appeared on the horizon"
come into being or existence, or appear on the scene; "Then the computer came along and changed our lives"; "Homo sapiens appeared millions of years ago"
be issued or published; "Did your latest book appear yet?"; "The new Woody Allen film hasn't come out yet"
appear as a character on stage or appear in a play, etc.; "Gielgud appears briefly in this movie"; "She appeared in `Hamlet' on the London stage"
seem to be true, probable, or apparent; "It seems that he is very gifted"; "It appears that the weather in California is very bad"
present oneself formally, as before a (judicial) authority; "He had to appear in court last month"; "She appeared on several charges of theft"